Asbestos: Principal properties
Definition and characteristics
Asbestos is the generic name given to a group of silicate minerals (iron, calcium, magnesium, etc.), with a fibrous and crystalline structure, and that can be divided into filaments. This mineral can be found in all parts of the world and is extracted in open pit mines. The main mines are in the US, Canada, South Africa, China and the former Soviet Union.
The excellent insulating properties, mechanical, chemical, heat and flame resistance, as well as their relative low cost, explains the numerous industrial and domestic applications for which it has been in use since 1970. As a curiosity, the term comes from the Greek language and means indestructible or unquenchable, referring to the properties of these mineral fibres.
They can be classified by their nature in two major groups: serpentine and amphibole. In the first group is the chrysotile (white asbestos) and part of the second group are Crocidolite (blue asbestos) and Amosite (brown asbestos).
Products that contain asbestos
Products that contain this product are divided into two large groups: friable and non-friable.
In non-friable asbestos, fibres are mixed with other materials, usually cement, glue or resins. The most commonly known are the corrugated asbestos cement. Other applications are also very widespread such its use as gutters, water tanks and pipes.
In friable asbestos, the fibres tend to break off easily, because they are not combined to another material. Some of the best-known applications are projected asbestos, cords, seals, insulation panels and fireproof clothing.
A piece of information that allows us to assess the magnitude of its use in Spain, is that in the period 1970-1990 approximately 2.6 million tonnes of asbestos was imported. With respect to these products, there are several studies that estimate that in Spain 1.7 million tonnes of non-friable element was installed (95 %) and between 40.000 and 120.000 tonnes of friable asbestos installed.
Problems caused by its use
The simple fact of being in contact with this product does not pose a significant risk however, before its prohibition it was known that the fibres, due to its small size and its long thin shape (and therefore readily airborne), were causing respiratory problems. During the 1990’s (Council Directive 91/655/EEC) when asbestos was declared as a carcinogenic substance and that it may be the cause of diseases such as asbestosis, lung cancer or malignant mesothelioma. The European Union banned all use of this product as from January the 1st 2005 through the EC Directive 1999/77.
In Spain, blue asbestos was banned in 1984 and brown type banned in 1993. From 2001 onwards, the manufacture and commercialisation of white asbestos was banned. Finally, in December 2002 the total prohibition of any activity (production, sale and installation) related to this product went into effect.
Since 2002, the removal of asbestos is subjected to strict legislation both for its controlled and safe removal as well as its subsequent elimination from the environment.
Publicado el 01/07/14